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HomeMy WebLinkAboutDRC-2016-004799 - 0901a0688061648d.■'-VW*afcC--A\ j&t ?~i /iV>>*5/ -Nw-wJ * I*,/''' State of Utah GARY R HERBERT Governor SPENCER J COX Lieutenant Governor Department of Environmental Quality Alan Matheson Executive Director DIVISION OF WASTE MANAGEMENT AND RADIATION CONTROL Scott T Anderson Director MEMORANDUM TO: Phil Goble /^°1 ^ FROM: Dean Henderson fy'?" DATE: October 23,2015 SUBJECT: Review of the 1st and 2nd Quarter 2015 Chloroform Monitoring Reports for the Chloroform Contamination Investigation, Energy Fuels Resources (USA) Inc. (“EFR“) * White Mesa Uranium Mill, near Blanding, Utah The Utah Division of Waste Management and Radiation Control (“Division”) has reviewed the May 20, 2015, 1st Quarter 2015 Chloroform Monitoring Report (“1st Report”) and August 25, 2015, 2nd Quarter 2015 Chloroform Monitoring Report (“2nd Report”) for the Chloroform Contamination Investigation. For the review of this report the following regulatory enforcement documents were used: • EFR issued Ground Water Quality Discharge Permit No. UGW370004 (“Permit”) on March 8, 2005; last revised on June 8, 2013. • The EFR Quality Assurance Plan (“QAP”) June 7, 2012 (Revision. 7.2) REVIEW Monitor Well Sampling The following monitor wells were sampled as required in the QAP. Monitor well TW4-37 was sampled for the first time in 2nd quarter 2015 monitoring event (see Table 1 below): MW-4 MW-26 MW-32 TW4-1 TW4-2 TW4-3 TW4-7 TW4-8 TW4-9 TW4-10 TW4-11 TW4-12 TW4-18 TW4-19 TW4-20 TW4-21 TW4-22 TW4-23 TW4-28 TW4-29 TW4-30 TW4-31 TW4-32 TW4-33 195 North 1950 West • Salt Lake City, UT Mailing Address PO Box 144880 • Salt Lake City, UT 84114-4880 Telephone (801) 536-0200 • Fax (801) 536-0222 "TDD (801) 536-4414 www deq utnh gov Printed on 100% recycled paper Page 2 TW4-4 TW4-5 TW4-6 TW4-13 TW4-14 TW4-16 TW4-24 TW4-25 TW4-26 TW4-27 TW4-34 TW4-35 TW4-36 TW4-37 In each quarter the monitoring wells were purged using the three approved QAP well purging strategies and meet QAP requirements for each strategy: 1. Purging two casing volumes with stable field parameters for specific conductivity, turbidity, pH, redox potential, and water temperature (within 10% RPD): Wells: MW-32, TW4-5, TW4-8, TW4-9, TW4-16, TW4-18, TW4-21 (1st quarter only), TW4-23, and TW4-32. 2. Purging a well to dryness and stability of field parameters for pH, specific conductivity, and water temperature only after recovery: Wells: TW4-2(15'quarter only), TW4-3, TW4-6, TW4-7, TW4-10, TW4-13, TW4-14, TW4-26, TW4-27, TW4-28, TW4-29, TW4-30, TW4-31, TW4-33, TW4-34, TW4-35 and TW36. 3. Pumping Wells: MW-4, MW-26, TW4-l(started pumping in 1st quarter), TW4-2(started pumping in 1st quarter), TW4-4, TW4-11 (started pumping in 1st quarter), TW4-19, TW4-20, TW4-21 (started pumping in 2nd quarter) TW4-22, TW4-24, TW4-25, and TW4-37(started pumping in 2nd quarter). The water samples for the above wells were analyzed for the following constituents as required in the QAP: Chloroform, Chloromethane, Carbon tetrachloride, Methylene chloride, Chloride and Nitrate + Nitrite as Nitrogen. The analytical methods used is consistent with the requirements of the QAP requirements. QAQC Holding Times The method holding times for each parameter for samples collected at each monitor well were received and analyzed within the required holding times in the QAP. Receipt Temperature All samples were received within the required QAP temperature limit of 6° C. Detection Limits All analytes were measured and reported to the required reporting limits. However, several sets of sample results had the reporting limit raised for at least one analyte due to matrix interference and/or Page 3 sample dilution. In all cases the reported value for the analyte was higher than the increased detection limit. Sample Duplicates In the 1st quarter monitoring event two duplicate samples were collected. Monitor well TW4-32 and its duplicate sample TW4-65 and TW4-5 and its duplicate sample TW4-70. All analytical results for the two sample/duplicate pairs were within the 20% acceptance limits (as required in the QAP). In the 2nd quarter monitoring event two duplicate samples were collected. Monitor well TW4-3 and its duplicate sample TW4-65, monitor well TW4-18 and its duplicate sample TW4-70. All analytical results for the two sample/duplicate pairs were within the 20% acceptance limits (as required in the QAP), with the exception of nitrate in TW4-3 and TW4-18, (see Table 2 below). The reported nitrate concentration for TW4-3 and TW4-65 was 5.7 mg/1 and 3.94 mg/1 respectively (RPD 36.5%). The reported nitrate concentration result for TW4-18 and TW4-70 was 9.69 mg/1 and 7.7 mg/1 respectively (RPD 22.9%). EFR noted these exceedances and responded: “ ...duplicate results outside of acceptance limits was implemented during the quarter for the results in duplicate pairs TW4-3/TW4-65 and TW4-18/TW4-70. The corrective action that were taken in accordance with the QAP procedure are as follows: the QA Manager contacted the Analytical Laboratory and requested a review of the raw data to assure that there were no transcription errors and the data were accurately reported. The laboratory noted that the data were accurate and reported correctly. Reanalysis was not completed as the samples were beyond the holding time. ” Based on EFR response in these circumstances it is recommended that there be no enforcement action but use the higher nitrate concentration for TW4-3 (5.7 mg/1) and use the higher nitrate concentration for TW4-18 (9.96 mg/1) for compliance purposes. Groundwater Head Monitoring Depth to groundwater was measured in the following wells and/or piezometers, as required in Part I.E.3 of the Permit: • The quarterly groundwater compliance monitoring wells. • Existing monitoring well MW-4 and all of the temporary chloroform investigation wells. • Piezometers P-1, P-2, P-3, P-4 and P-5. • MW-20 and MW-22. • Nitrate monitoring wells. • The DR piezometers which were installed during the Southwest Hydrologic Investigation. In addition, weekly and monthly depth to groundwater measurements were taken in MW-4, MW-26, TW4-1, TW4-2, TW4-4, TW4-11, TW4-19, TW4-20, TW4-21, TW4-22, TW4-24, TW4-25, TW4-37 and TWN-2. Mass Removed Chloroform removal was first estimated from the first quarter 2007. Since that estimation the mass removed by each pumping well for each quarter has been calculated. Estimated reported mass removed in 1st quarter 2015 is 9.9 lbs. and 2nd quarter 2015 is 15.3 lbs. Table 3 below verifies this estimate. Page 4 Reporting The Report included the following information as required in the QAP: a) Introduction b) Sampling and Monitoring Plan -Description of monitor wells -Description of sampling methodology, equipment and decontamination procedures -Identify all quality assurance samples, e.g. trip blanks, equipment blanks, duplicate samples c) Data Interpretation -Interpretation of groundwater levels, gradients, and flow directions. Interpretations will include a discussion on: 1) A current site groundwater contour map, 2) hydrographs to show groundwater elevation in each monitor well over time, 3) depth to groundwater measured and groundwater elevation from each monitor well summarized in a data table, that includes historic groundwater level data for each well, and 4) an evaluation of the effectiveness of hydraulic capture of all contaminants of concern. -Interpretation of all analytical results for each well, including a discussion on: 1) a current chloroform isoconcentration map with one of the isoconcentration lines showing the 70 pg/L boundary, 2) graphs showing chloroform concentration trends in each well through time and, 3) analytical results for each well summarized in a data table, that includes historic analytical results for each well. -Calculate chloroform mass removed by pumping wells. Calculations would include: 1) total historic chloroform mass removed, 2) total historic chloroform mass removed for each pumping well, 3) total chloroform mass removed for the quarter and, 4) total chloroform mass removed from each pumping well for the quarter. d) Conclusions and Recommendations e) Electronic copy of all laboratory results for Chloroform Investigation monitoring conducted during the quarter. f) Copies of DUSA field records, laboratory reports and chain of custody forms. Evaluation of the Chloroform Contaminate Plume and Its Associated Contaminants Bounding Chloroform Plume Groundwater monitoring data up to the 2nd quarter 2015 monitoring event appeared to show that the chloroform contaminate plume (“Plume”) and associated contaminants, carbon tetrachloride, chloromethane, and methylene chloride is bound by up gradient, cross gradient, and down gradient wells that have a chloroform concentration of <70 pg/L (GWQS = 70 pg/L). Page 5 Monitor Wells Exceeding Chloroform Concentrations GWQS of 70ug/L Six monitor wells: TW4-6, TW4-7, TW4-8, TW4-10, TW4-21, TW4-29, and TW4-33. Monitor Wells with Chloroform Concentrations between 1 pg/L and 70pg/L Eight monitor wells: TW4-5, TW4-9, TW4-14, TW4-16, TW4-18, TW4-24, TW4-26, and TW4-28 For the first time since sampling began (4th quarter 2006) at well TW4-14 it exceeded the chloroform minimum detection limit of <1.0 pg/L for both the 1st quarter and 2nd quarter 2015 monitoring events at 1.7 and 1.82 pg/L respectively (see Table 1 below). TW4-14 helps define the eastern boundary area of the chloroform plume. No action is recommended but a close watch on this monitor well will be done to see if chloroform increase to above 70 pg/L. For the first time since sampling began (2nd quarter 2013) at well TW4-30 it exceeded the chloroform minimum detection limit of <1.0 pg/L for both the 1st quarter and 2nd quarter 2015 monitoring events at 1.65 and 2.25 pg/L respectively (see Table 1 below). TW4-30 helps define the southern boundary area of the Plume and is located approximately 800 feet east and down gradient of TW4-29 that as of the 2nd quarter monitoring event has a reported chloroform concentration of 329 pg/L (see Table 1 below). The leading edge of Plume may be approaching TW4-30. No action is recommended but a close watch on this monitor well be done to see if chloroform increase to above 70 pg/L. Pumping Wells Three new pumping wells TW4-1, TW4-2, and TW4-11 started in the 1st quarter 2015 and two new pumping wells TW4-21 and TW4-37 in the 2nd quarter 2015. There are now 13 pumping wells. MW-4, MW-26, TW4-1, TW4-2, TW4-4, TW4-11, TW4-19, TW4-20, TW4-21 TW4-22 and TW4-37 exceed chloroform concentrations of 70pg/L. Pumping well TW4-24 had a chloroform concentration of 4.28 pg/L and TW4-25 had non-detectable chloroform concentrations (<1.0 pg/L). Monitor Wells Below the Laboratory Chloroform Detection Limit (<1.0 pg/L) The following monitor wells are below the laboratory detection limit for chloroform (<1.0 pg/L): MW- 32, TW4-3, TW4-12, TW4-13, TW4-23, TW4-27, TW4-28, TW4-31, TW4-32, TW4-34, TW4-35 and TW4-36. Nitrate. Nitrate + Nitrite (“nitrate”) Concentrations Monitor wells TW4-21, TW4-22, TW4-24, and TW4-25 all exceed the nitrate GWQS of 10 mg/1. All of these nitrate exceedances for these wells appear to be a result of the nitrate contaminant plume up- gradient of the chloroform contaminant plume. This nitrate contaminant plume is being addressed under the Nitrate Corrective Action Plan, approved on December 12, 2012. Conclusions on Compliance with the Permit and QAP Per the Division review it appears that the Reports comply with Permit and QAP. Therefore a letter will be drafted for the Director Signature, notifying EFR of the review and closing out of the 1st and 2nd, Quarter 2015 Chloroform Monitoring Reports for the chloroform contamination investigation. TABLE 1 (1 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride ______(5 M9/L)______ Chloroform (70 im/L) Chloromethane ___(3Q pg/i)___ Parameter (GWQS) Methylene Chloride _____(5 Mfl/L)_____ Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite ______(10 mg/L)______ MW-4 (chloroform pumping well) 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <10 <50 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <50 <50 <50 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 2,900 3,170 3,500 3,000 NA NA <10 <50 2.1 3,100 3,000 2,820 2,830 <50 <50 <50 1.4 NA NA <10 <50 <50 <50 <50 <1.0 1.6 1.8 1.9 1.7 2,300 2,000 2,600 2,300 <1.0 <1.0 <1.0 <1.0 1.7 1.8 1.8 1.7 2,400 2,500 1,800 2,100 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA NA 53 49 49 48 50 47 45 47 45 42 42 35 45 6.3 7.1 7.0 7.0 6 0 6.0 1.2 6.4 6.3 7.0 6.2 6.2 5.8 6.1 6.4 5.9 5.7 5.2 5.3 5.8 4.0 5.1 4.8 4.9 4.6 4.9 4.9 5.1 4.8 4.9 5.0 4.8 4.8 4.2 4.9 5.3 4.7 4.1 3.7 5.1 5.8 2.5 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/14/09 1st Qtr 2/17/10... 2nd Qtr 6/14/10 3rd Qtr 8/6/10 4th Qtr 10/15/10 1st Qtr 2/23/11 2nd Qtr 6/1/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 1st Qtr 1/23/12 2nd Qtr 6/6/12 3rd Qtr 9/4/12 4th Qtr 10/4/12 1st Qtr 2/11/13 2nd Qtr 6/5/13 3rd Qtr 9/3/13 4th Qtr 10/29/13 1st Qtr 1/27/14 2nd Qtr 5/19/14 3rd Qtr 8/11 /14 4th Qtr 10/21/14 <1.0 1st Qtr 3/9/15 2nd Qtr 6/8/15 1.5 1.3 1.4 1.6 2,200 1,800 2,000 1,800 <1.0 <1.0 <10 <1.0 1.2 1.2 1.5 1.4 1,600 2,100 1,900 1,500 <10 <1.0 <1.0 <1.0 1.5 1.4 1.1 1.3 1,700 1,700 1,700 1,600 <1.0 <1.0 <1.0 <1.0 1 1.2 1.5 1 1,500 1,400 1,500 1,300 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 <1.0<1.6 <1.0 <1.0 <1.0<1,6 <1.0 <1.0 <1.0 1.48 1.31 1.13 5.58 1,670 1,490 1,520 1,410 <1.0 <1.0 <1.0 <1.0 4.15 5.21 7.6 1,390 1,390 1,490 1,440 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1.26 <1.0 1,400 1,300 <1.0 <1.0 <1.0 <1.0 37 34 43 44 45 41 38 41 40 35 41 40 41 39 41 41 37.8 44 41.4 40.1 38.5 39.9 41 41.5 407 43.1 MW-4A(TW4-A) 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <10 <50 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/05 4th Qtr 11/8/05 1st Qtr 2/28/07 <50 <50 <50 3,700 3,740 3,800 3,000 NA NA <10 <50 NA NA <10 <50 2.4 1.9 3,700 3,300 3,190 3,370 <50 <50 <50 <1.0 <50 <50 <50 <1.0 2,500 <1.0 <1.0 Well abandonded NA NA NA 55 53 54 54 54 60 7.1 7.8 6.9 6.7 5.8 7.3 1.2 7.1 7 1 NA = not analyzed Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS. TABLE 1 (2 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride ______(5 ng/L)______ Chloroform (70 ng/L) Chloromethane ___(30 H9'L)___ Parameter (GWQS) Methylene Chloride ______(5 ML)_____ Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite (10 mg/L) MW-26 (former TW4- 15) Chloroform pumping well 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <5.0 <50 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <50 <50 <50 <1.0 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 11/18/08 <1.0 <1.0 <1.0 NA <2.0 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/14/09 1st Qtr 2/17/10 2nd Qtr 6/14/10 3rd Qtr 8/16/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/23/11 2nd Qtr 5/31/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 (1)12/5/11 <1.0 <1.0 <1.0 NA <1.0 1st Qtr 2/7/12 2nd Qtr 6/6/12 3rd Qtr 9/4/12 4th Qtr 10/4/12 <1.0 <1.0 <1 <1 1st Qtr 2/11/13 2nd Qtr 6/5/13 3rd Qtr 9/3/13 4th Qtr 10/29/13 1st Qtr 1/27/14... 2nd Qtr 5/19/14 3rd Qtr 8/11 /14 4th Qtr 10/21/14 <1 <1.0 <1.0 <1.0 <10 <1.0 <1.0 <1.01st Qtr 3/9/15 2nd Qtr 6/8/15 <1.0 <1.0 310 442 960 1,000 NA NA 5.4 <50 1,100 830 2,170 282 <50 <50 <50 <1.0 570 300 1,400 2,000 <1.0 <1.0 <1.0 <1.0 NA 930 1,300 630 1,700 ....950 410 850 1,100 <1.0 <1.0 <1.0 NA <2.0 1.2 730 1,600 2,200 970 <1.0 <1.0 <1.0 <1.0 <10 <1.0 <1.0 <1.0 450 1,800 720 NA 1,800 2,400 3,000 3,100 1,200 <1.0 <1.0 <1.0 NA <1.0 <io“ <1.0 <1 <1 2,120 4,030 2,940 1,410 <1 <1.0 <1.0 <1 1,400 1,960 2,120 2,090 1,980 1,980 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA <5.0 <50 <50 <50 <50 NA <1.0 8.7 NA NA NA 2.6 5.5 13 36 14 40 53 24 100 NA 51 12 30 40 19 21 6.5 3.6 1.3 7.2 NA 2.9 16 21 31 4 9.34 52.4 33.2 4.03 13.8 15.4 26 23.2 27.4 11.2 55 52 52 65 54 56 49 57 57 49 57 44 64 49 48 46 60 57 40 49 65 57 88 58 69 NA 98 73 73 68 81.9 77.9 60.5 72.3 59.4 53.4 59 60.1 56.5 62 NA 0.3 0.2 0.2 0.3 0.2 0.2 1.4 0.3 0.6 0.4 1 0.66.1 0.6 0.2 0.1 0.4 0.2 0.1 2.3 6.2 6.8 0.6 0.7 0.5 0.4 0.9 2.0 NA 17 2.5 2.6 1.8 2 3 2.1 1.2 1.4 05 0.9 0.7 0.9 0.7 0.4 (1) VOCs were resampled because laboratory missed holding NA = not analyzed Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS. time. TABLE 1 (3 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride (5 Iig/L) Chloroform (70 Pfl/L) Chloromethane (30 pg/L) Parameter (GWQS) Methylene Chloride (5 mh/U Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite ______(10 mg/L)______ MW-32 (former TW4- 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 >-17) 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/16/09 1st Qtr 2/17/10 2nd Qtr 6/14/10 3rd Qtr 8/16/10 4th Qtr 10/15/10 1st Qtr 2/23/11 2nd Qtr 5/25/11 3rd Qtr 8/16/11 4th Qtr 11/16/11 <1> 12/7/1 NA NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1 0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1 0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <1.0 NA NA <1.0 <10 3.2 3.5 1.8 15 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1,0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <1.0 NA NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0<io <1.0 <1.0 <1.0<1.6 <1.0 <1.0 <1.0 <1,0 <1.0 <1.0 <1.0 <1 0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <1.0 <1.6 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA NA NA 33 32 30 32 31 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <1.0 <1 32 32 31 32 <1.0 <1.0 <1.0 <1.0 31 29 30 26 30 31 33 35 <.1 <1.0 <1.0 <0.05 <.1 <0.1 <0.1 <0.1 38 32 28 24 <0.1 <0.1 <0.1 <0.1 40 31 33 32 <0.1 <0.1 <0.1 <0.1 NA 1st Qtr 1/18/12 2nd Qtr 6/22/12 3rd Qtr 9/5/12 4th Qtr 10/10/12 1st Qtr 2/11/13 2nd Qtr 6/18/13 3rd Qtr 9/3/13 4th Qtr 10/29/13 1st Qtr 1/29/14 2nd Qtr 5/23/14 3rd Qtr 8/26/14 4th Qtr 10/29/14 <1.0 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 <1.0 1st Qtr 3/17/15 2nd Qtr 6/11/15 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 21 32 33 35 34.3 34.9 33 35.7 <0.1 <0.1 <0.1 <0.1 <67 <0.1 <0.1 <0.1 34 39.7 34 34.9 <0.1 <0.1 <0.1 <0.1 36.3 35.8 <0.1 <0.1 (1) VOCs were resampled because laboratory missed holding time. NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (4 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride ______(5 ng/L)______ Chloroform (70 pg/L) Chloromethane ___(3QH9/L)___ Parameter (GWQS) Methylene Chloride _____(5_M9(L)_____ Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-1 (chloroform pumping well) 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 1st Qtr 3/3/10 2nd Qtr 6/14/10 3rd Qtr 8/18/10 4th Qtr 10/15/10 1st Qtr 2/24/11 2nd Qtr 6/1/11 3rd Qtr 8/18/11 4th Qtr 11/29/11 1st Qtr 1/24/12 2nd Qtr 6/14/12 3rd Qtr 9/28/12 4th Qtr 10/4/12 1st Qtr 2/13/13 2nd Qtr 6/19/13 3rd Qtr 9/3/13 4th Qtr 11/14/13 1st Qtr 2/5/14 2nd Qtr 5/23/14 3rd Qtr 8/27/14 4th Qtr 10/29/14 1st Qtr 3/9/15 2nd Qtr 6/8/15 NA NA <10 <50 <50 <50 <50 <1.0 <1.0 <1.0 <1.0 <10 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 2,700 3,080 2,900 2,400 1.4 2,700 2,200 2,840 2,260 NA NA <10 <50 <50 <50 <50 <1.0 1.2 1.4 1.3 1.3 1,900 1,900 2,300 2,000 <1.0 <1.0 <1.0 <1.0 1.3 1.1 1.3 1.3 2,000 1,900 1,700 1,700 <1.0 <1.0 <1.0 <1.0 1.1 1 1,700 1,500 1,700 1,400 <1.0 <1.0 <1.0 <1.0 1.2 1 1,300 1,600 1,600 1,500 <1.0 <1.0 <1.0 <1.0 1,300 1,200 1,300 1,500 1,300 1,000 1,000 1,100 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 3.66 1,320 1,100 1,150 1,280 <1.0 <1.0 <1.0 <1.0 5.47 4.77 1,090 1,020 845 1,140 1,130 1,260 <1.0 <1.0 <1.0 <1 0 <1.0 NA NA <10 <50 <50 <50 <50 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1.4 <1.0 <1.0 <1.0 <1.0 <10 <1.0 <1,0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA NA 52 49 48 51 47 47 45 43 43 39 39 35 41 37 37 36 41 35 40 35 40 41 35 36 40 38 42 39 40 37.6 39.1 37.6 36.5 38.9 37.4 38 38.7 38.3 40.3 9.1 10.6 9.8 9.7 94 9.6 9.2 8.9 9 8.4 7.8 7.6 8.68 8.15 9.3 7.5 6.9 7.3 6.8 7.1 6.8 6.7 6.6 6.6 6.6 6.8 6.6 6.8 7.1 5.0 6.5 7.0 6.9 7.1 7.1 7.7 6 9 4.8 6.3 7.1 6.1 NA = not analyzed Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS. TABLE 1 (5 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride (5 Hfl/L) Chloroform (70 pg/L) Chloromethane (30 pg/L) Parameter (GWQS) Methylene Chloride (5 pg/L) Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-2(chloroform pumping well) 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 11/18/08 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 1st Qtr 3/3/10 2nd Qtr 6/14/10 3rd Qtr 8/18/10 4th Qtr 10/15/10 1st Qtr 2/24/11 2nd Qtr 6/2/11 3rd Qtr 8/17/11 4th Qtr 11/29/11 1st Qtr 1/24/12 2nd Qtr 6/14/12 3rd Qtr 9/28/12 4th Qtr 10/4/12 1st Qtr 2/13/13 2nd Qtr 6/19/13 3rd Qtr 9/3/13 4th Qtr 11/14/13 1st Qtr 2/6/14 2nd Qtr 5/23/14 3rd Qtr 8/27/14 4th Qtr 10/30/14 1st Qtr 3/9/15 2nd Qtr 6/8/15 NA NA <10 <50 <50 <50 <50 NA 3,700 3,750 3,900 3,500 NA NA <10 <50 2.3 1.8 2.5 2.2 2.1 3,800 3,200 4,120 3,420 <50 <50 <50 <1.0 2,300 3,000 340 (?) 3,200 <1.0 <1.0 <1.0 <1.0 2.3 2.2 24 24 NA 3,300 3,100 2,800 3,200 <1.0 <1.0 <1.0 NA <2.0 2.2 2 2 2 3,100 2,800 3,000 1,600 <1.0 <1.0 <1.0 <1.0 2 2.6 2.5 2.1 2,600 3,300 3,300 3,000 <1.0 <1.0 <1.0 <1.0 2.4 2.2 1.6 2.8 3,100 3,000 2,400 3,900 <1.0 <1.0 <1.0 <1.0 2 2.1 1.8 2 5.17 2.65 2.41 3.15 2,500 2,500 2,900 3,100 <1.0 <1.0 <1.0 <1.0 3,580 3,110 3,480 3,740 7.1 6.05 1.4 2.6 3,180 2,930 3,170 3,580 <1.0 2 <1.0 <1.0 <1 0 <1.0 <1.0 1.44 <1.0 1,840 1,650 <1.0 <1.0 NA NA <10 <50 <50 <50 <50 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 3.6 <1,0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA NA NA 56 56 56 54 55 54 50 49 51 48 46 42 47 NA 46 44 43 46 42 43 43 41 46 42 48 49 49 52 76 49 46 46.9 44 9 43.9 459 45.4 45 45.5 44.9 48.1 7.7 8.6 8.0 7.8 7.5 7.1 7.4 7.6 7.3 7.8 7.3 6.9 6.9 7.4 7.1 8.0 6.5 6.4 6.6 6.4 6.8 8.7 6.6 6.5 7.0 6.8 6.0 7.0 7.1 7.7 4.0 7.6 8.1 7.5 9.3 8.4 7.9 9.1 6.2 8.5 5.3 4.3 NA = not analyzed Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS. TABLE 1 (6 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride ______(5 pg/i)______ Chloroform (70 Hfl/L) Chloromethane ___(30 mm___ Parameter (GWQS) Methylene Chloride _____(5 mm_____ Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite ______(10 mg/L)______ TW4-3 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <1.0 <1.0 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 <1.0 <10 <1.0 <1.0 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/23/10 2nd Qtr 6/14/10 3rd Qtr 8/10/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/15/11 2nd Qtr 5/25/11 3rd Qtr 8/16/11 4th Qtr 11/14/11 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/17/12 2nd Qtr 5/31/12 3rd Qtr 8/29/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 <1.0 <1,0 <1.0 <1.0 NA NA <1.0 6.4 <1.0 <1.0 <1.0 <1.0 <10 <1.0 <1.0 <1.0 2.3 1.6 2.2 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <10 <1.0 <1.0 <1.0 <10 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <i.6 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1,0 <1.0 NA NA NA 26 26 26 26 23 22 23 24 27 21 19 19 22 21 20 21 22 23 24 22 26 23 23 23 23 21 24 25 25 3.5 3.7 3.5 3.3 3.3 7.1 2.9 1.5 3.1 3.3 3.1 2.8 2.8 2.9 2.7 2.6 2.5 2.9 2.8 2.6 2 8 3.0 3.1 3.3 3.5 3.7 4.0 4.4 7.1 4.4 4.9 4.8 5.1 5.8 4.9j 5.9 6.7 6.0 5.3 6.1 6.6 5.7 3.9 1st Qtr 2/7/13 2nd Qtr 6/29/13 3rd Qtr 9/3/13 4th Qtr 11/6/13 1st Qtr 1/22/14 2nd Qtr 5/21/14 3rd Qtr 8/13/14 4th Qtr 10/23/14 <1.0 <1.0 <1.0 <1.0 <1 0 <1.0 <1.0 <1.0 1st Qtr 3/11/15 2nd Qtr 6/10/15 Duplicate TW4-65 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 23.7 23.8 25 24.1 24.9 24.4 26 26.7 26.2 27.5 27.5 NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (7 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride (5 van.) Chloroform (70 pg/L) Chloromethane (30 Hfl/L) Parameter (GWQS) Methylene Chloride (5 nfl/L) Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-4 (chloroform pumping well) 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <10 <50 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <50 <50 <50 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 4th Qtr 11/18/09 NA <2.0 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 1st Qtr 2/17/10 2nd Qtr 6/14/10 3rd Qtr 8/10/10 4th Qtr 10/15/10 1st Qtr 2/23/11 2nd Qtr 6/1/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 <1.0 1st Qtr 1/23/12 2nd Qtr 6/6/12 3rd Qtr 9/4/12 4th Qtr 10/3/12 <1.0 <1.0 1st Qtr 2/11/13 2nd Qtr 6/29/13 3rd Qtr 9/3/13 4th Qtr 10/3/13 <1.0 1st Qtr 1/27/14 2nd Qtr 5/19/14 3rd Qtr 8/11/14 4th Qtr 10/21/14 1st Qtr 3/9/15.... 2nd Qtr 6/10/15 <1.0 <1.0 1.7 1.5 1.7 1.5 1.5 1.6 1.5 1.4 NA 1.2 1.2 1.1 1.1 1 1.2 1.3 1.3 1.4 1.2 1.2 1 1 1.2 5.3 3.88 4.94 4.94 1.05 3,100 2,400 3,200 2,800 NA NA <10 <50 2,900 2,600 2,850 2,670 2,200 2,400 2,700 2,500 <50 <50 <50 <1.0 <1.0 <1.0 <1.0 <1.0 2,800 2,500 2,200 2,500 2,200 1,800 2,000 950 1,700 1,700 2,100 1,700 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1,800 1,700 1,500 1,500 1,200 1,500 1,600 1,400 <1.0 <1.0 <1.0 <1.0<176 <1.0 <1.0 <1.0 1,460 1,330 1,380 1,360 1,260 1,220 1,320 1,130 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1,350 1,280 <1.0 <1.0 NA NA <10 <50 <50 <50 <50 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 7.1 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA NA NA 54 51 48 50 49 49 47 45 47 43 42 39 44 NA 37 34 39 41 48 35 36 38 41 35 40 39 38 43 39 38 39 39.6 38.8 43.9 37.4 47.5 40 40 37.6 41.3 10.0 11.3 9.9 10.2 9.5 8.6 9.7 10.1 9.0 9.4 9.5 9.5 9.2 10.8 8.8 10.1 10.2 8.2 8.4 7.6 6.6 7.6 7.3 7.1 7 0 7.0 6.6 7.0 7.1 7.1 7.1 7.0 7.4 6.3 7.2 7.8 7.3 5.9 5.3 7.0 7.7 6.3 NA = not analyzed Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS. TABLE 1 (8 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride (5 MB/L) Chloroform (70 pg/L) Chlorometha'ne (30 MH/L) Parameter (GWQS) Methylene Chloride _____(5 Mg/L)_____ Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-5 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <2.5 <2.5 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <2.5 <2.5 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 1st Qtr 2/25/10 2nd Qtr 6/14/10 3rd Qtr 8/11/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/22/11 2nd Qtr 5/26/11 3rd Qtr 8/7/11 4th Qtr 11/16/11 (,) 12/7/11 <1.0 <1.0 <1.0 NA <1.0 1st Qtr 1/18/12 2nd Qtr 6/6/12 3rd Qtr 9/11/12 4th Qtr 10/3/12 <1,0 <1.0 <1.0 <1.0 1st Qtr 2/13/13 2nd Qtr 6/13/13 3rd Qtr 9/5/13 4th Qtr 11/13/13 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/30/14 2nd Qtr 5/22/14 3rd Qtr 8/14/14 4th Qtr 11/13/13 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/12/15 Duplicate TW4-70 2nd Qtr 6/10/15 <1.0 <1.0 <1.0 120 113 82 63 NA NA 66 51 53.7 47.1 5.8 2.5 3.1 3.1 35 26 9.2 9.4 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 11 9.3 11 10 <1.0 <1.0 <1.0 <1.0 12 13 12 8.5 <1.0 <1.0 <1.0 <1.0 13 12 12 11 <1.0 <1.0 <1.0 <1.0 NA 10 9 10 7.9 7.6 8.4 12 8 <1.0 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 <1.0 10.8 11.2 11.6 14.4 <1.0 <1.0 <1.0 <1.0 12.5 13.4 12.0 14.6 <1.0 <1.0 <1.0 <1.0 13.8 13.8 13.3 <1.0 <1.0 1.07 NA NA <2.5 <2.5 <2.5 <2.5 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1 0 <1.0 <1.0 NA NA NA NA 56 52 51 54 55 57 45 38 39 36 37 34 37 34 37 48 41 43 28 38 41 34 35 37 30 NA 22 39 37 38 34.3 36.5 39.1 41.1 40.5 51.4 44 45.1 45.1 46.4 47.3 4.9 3.7 6.0 6.0 6.0 5.9 6.7 2.9 7.8 7.0 7.7 8.2 7.4 8.7 7.9 9.3 7.9 7.5 8.3 7.5 68 7.1 7.0 7.2 7.0 7.2 7.5 6.0 5.8 8.0 8.1 7.7 8.2 10.7 7.8 7.8 9.2 7.8 7.2 8.3 93 8.8 7.1 (1) VOCs were resampled because laboratory missed holding NA = not analyzed Shaded indicates concentrations exceeding GWQS. time. TABLE 1 (9 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride ______(5 ng/L)______ Chloroform (70 pg/L) Chloromethane ___(30 pg/L)___ Parameter (GWQS) Methylene Chloride (5 pg/L) Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite ______(10 mg/L)______ TW4-6 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <1.0 <1.0 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <1.0 <1.0 <1.0 <10 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/25/10 2nd Qtr 6/14/10 3rd Qtr 8/11/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/23/11 2nd Qtr 5/26/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 <1) 12/7/11 <2) 11/16/11 <1.0 <1.0 <1.0 NA <1.0 <1.0 1st Qtr 1/18/12 2nd Qtr 6/13/12 3rd Qtr 9/11/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/13/13 2nd Qtr 6/13/13 3rd Qtr 9/5/13 4th Qtr 11/13/13 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/29/14 2nd Qtr 5/22/14 3rd Qtr 8/14/14 <3)3rd Qtr 9/24/14 4th Qtr 10/29/14 1st Qtr 3/12/15 2nd Qtr 6/10/15 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 2.5 10 17 NA NA 31 19 11 42.8 <1.0 <1.0 <1.0 <1.0 46 11 18 18 <1.0 <1.0 <1.0 <1.0 52 24 39 37 <1.0 <1.0 <1.0 <1.0 81 120 280 250 <1.0 <1.0 <1.0 <1.0 1000 590 630 420 <1.0 <1.0 <1.0 <1.0 NA 47 9.6 16 21 50 <1.0 <1.0 <1.0 NA <1.0 <1.0 38 4.7 6.9 9 <1.0 <1.0 <1.0 <1.0 6.89 4.86 5.93 5.51 5.7 10.3 202 260 723 1,180 1,040 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 2.8 1.3 NA NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0<1.6 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0<1.6 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0<1.6 <1.0 <1.0 <1.0 <1.0 <1.6 <1.0 NA NA NA NA 32 31 30 37 65 32 38 36 35 33 35 35 33 35 37 37 41 45 33 31 41 40 42 39 36 33 38 40 41 40 4 37.9 40.6 40.2 406 37 40 NA 41.1 NA 41.2 41.6 5.3 0.2 0.4 0.8 0.9 1.2 1.0 0.6 1.4 1.8 0.6 0.7 0.8”Ti 0.9 1.1 1.0 2.2 2.7 5.0 6.1 1.8 2.5 3.9 4.3 0.7 0.3 0.3 0.8 NA 0.8 6.7 0.2 0.1 0.2 0.2 0.2 0.2 1.5 0.2 0.3 4.2 6.9 5.9 (1) VOCs were resampled because laboratory missed holding t (2) Results of the TW4-70 the duplicate sample for TW4-6. (3) Reanalyzed for VOCs only. NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (10 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride ______(5 ng/L)______ Chloroform (70 pg/L) Chloromethane ___(30 pg/L)___ Parameter (GWQS) Methylene Chloride _____(5 ng/L)_____ Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-7 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <10 <50 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <50 <50 <50 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 11/18/08 NA <2.0 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 1st Qtr 3/3/10 2nd Qtr 6/14/10 3rd Qtr 8/11/10 4th Qtr 10/15/10 1st Qtr 2/23/11 2nd Qtr 6/1/11 3rd Qtr 8/18/11 4th Qtr 11/29/11 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1,0 <1.0 <1.0 1st Qtr 1/19/12 2nd Qtr 6/14/12 3rd Qtr 9/13/12 4th Qtr 10/4/12 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/13/13 2nd Qtr 6/18/13 3rd Qtr 9/12/13 4th Qtr 11/14/13 <1.0 <1.0 <1,0 <1.0 1.5 1.1 1.5 1.4 1.2 1.3 1.3 1.4 NA 1.2 1 3,100 2,700 3,100 2,500 NA NA <10 <50 1,900 2,200 2,140 2,160 <50 <50 <50 <1.0 1,830 2,600 2,300 1,900 <1.0 <1.0 <1.0 <1.0 2,200 1,800 1,600 2.500 1,800 1,400 1.500 1,300 <1.0 <1.0 <1.0 NA <2.0 1,200 1,100 1,500 1,100 <1.0 <1.0 <1.0 <1.0<1.6 <1.0 <1.0 <1.0 1,300 1,200 1,200 1,000 1,000 790 870 940 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 940 953 1,040 1,050 <1.0 <1.0 <1.0 <1.0 NA NA <10 <50 <50 <50 <50 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA NA NA 52 48 47 51 49 47 45 44 45 43 43 35 40 NA 35 37 37 37 35 31 36 38 45 35 37 37 37 41 40 41 37.7 39.3 36.4 37.2 "38.2 37.7 39 40.2 40 4 42.1 5.2 5.4 5.2 5.3 1 4.5 4.7 46 6 5.1 4.7 4.7 4.2 4.8 4.16 4.01 3.7 3.8 4.1 4.2 3.8 3.9 3.9 4 3.6 4 0 4.1 3 8 3.9 4.0 3.8 3.8 3.5 4.0 4.2 4.1 4.2 4.2 2.9 3.7 4.3 2.6 1st Qtr 2/5/14 2nd Qtr 5/22/14 3rd Qtr 8/27/14 4th Qtr 10/30/14 <1.0 <1.0 1st Qtr 3/18/15 2nd Qtr 6/11/15 <1.0 <1.0 5.41 4.78 946 847 857 926 942 950 <1.0 <1.0 1.5 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA = not analyzed Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS. TABLE 1 (11 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride ______(5 H9/L)______ Chloroform (70 pg/L) Chloromethane ___(30 pg/L)___ Parameter (GWQS) Methylene Chloride _____(5 pg/L)_____ Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-8 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <1.0 <1.0 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 10 1.1 NA NA <1.0 1.7 NA NA NA <1.0 1.3 1.8 2.1 1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 2.5 2.5 1.5 3.5 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA NA 41 39 37 39 40 <0.1 <1.0 <1.0 <1.0 <.1 39 42 42 43 <1.0 46 45 39 44 <1.0 <0.05 <0.05 0.2 0.3 0.1 0.7 0.2 0.5 0.1 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/17/09 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/24/10 2nd Qtr 6/14/10 3rd Qtr 8/18/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/16/11 2nd Qtr 5/25/11 3rd Qtr 8/16/11 4th Qtr 11/16/11 (1)12/7/11 1st Qtr 1/18/12 2nd Qtr 5/13/12 3rd Qtr 8/29/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/7/13 2nd Qtr 5/30/13 3rd Qtr 9/5/13 4th Qtr 11/7/13 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/23/14 <2)2/6/2014 2nd Qtr 5/22/14 3rd Qtr 8/27/14 4th Qtr 10/29/14 1st Qtr 3/12/15 2nd Qtr 6/11/15 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 63.8 100.0 122.0 107 191 <1.0 <1.0 <1.0 <1.0 <1.0 961 981 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA 42 44 44 51 57 42 45 46 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 52 45 46 45 <0.1 NA 45 44 48 47 <0.1 46.6 45.5 47.5 46.1 <0.1 <0.1 48.5 46.5 53 47 46.7 49.6 53 0.1 0.1 0.1 0 2 0.3 0.2 0.1 0.4 0.1 0.2 0.2 0.5 0.6 0.9 2 3 1.9 (1) VOCs were resampled because laboratory missed holding time. (2) Resampled to verity chloroform concentration that was collected on 1/23/14. NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (12 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride ______(5 H9'L)______ Chloroform (70 pg/L) Chloromethane (30 pg/L) Parameter (GWQS) Methylene Chloride (5 ng/L) Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-9 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <1.0 <1.0 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 <1.0 <1.0 <1.0 <1.0 <1.0 ' <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 3.8 1.2 <1.0 <1.0 NA NA <1.0 2.9 NA NA <1.0 <1.0 <1.0 <1.0 <1.0 19 2.6 2.7 <1.0 21 9.5 8.7 1.3 1 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1 0 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 NA <1.0<7.0 <1.0 <1.0 <1.0 <1 0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA NA 42 38 39 41 44 44 42 38 40 35 35 28 58 1.3 1.3 1.3 1.3 1.5 1.5 0.9 0.7 0.6 1.3 1.8 2 2.1 2.3 2.79 1.99 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/17/09 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/23/10 2nd Qtr 6/14/10 3rd Qtr 8/13/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/17/11 2nd Qtr 5/25/11 3rd Qtr 8/16/11 4th Qtr 11/16/11 (1) 12/7/11 <1.0 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 <1.0<7.6 <1.0 <1.0 <1.0 NA 30 30 30 37 47 33 40 34 41 38 21 38 2.5 2.3 2.5 1.7 1.4 1.5 1.2 1.8 1.3 3.4 4 2.3 1st Qtr 1/18/12 2nd Qtr 5/31/12 3rd Qtr 8/30/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/7/13 2nd Qtr 5/30/13 3rd Qtr 9/5/13 4th Qtr 11/7/13 1st Qtr 1/29/14 2nd Qtr 5/22/14 3rd Qtr 8/14/14 4th Qtr 10/29/141st Qtr 3/12/15... 2nd Qtr 6/11/15 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 6.9 47 101 <1.0 <1.0 <1.0 <1.0 53.5 35.1 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 28 23 22 21 20.6 21.4 22.7 23.6 22 24 27 25 29.5 35.3 2.3 4.0 3.9 3.8 4.5 4.5 4.0 4.9 4.4 3.4 2.7 4.3 3.3 1.8 (1) VOCs were resampled because laboratory missed holding time. NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (13 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride ______(5 ng/L)______ Chloroform (70 pg/L) Chloromethane (30 pg/L) Parameter (GWQS) Methylene Chloride (5 pg/L) Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-10 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <2.5 <2.5 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <5.0 <5.0 <5.0 <1.0 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1,0 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 11/18/08 <1.0 <1.0 <1.0 NA <2.0 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/22/09 1st Qtr 3/3/10 2nd Qtr 6/14/10 3rd Qtr 8/12/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/23/11 2nd Qtr 6/14/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/19/12 2nd Qtr 6/14/11 3rd Qtr 9/12/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/13/13 2nd Qtr 6/13/13 3rd Qtr 9/12/13 4th Qtr 11/14/13 1st Qtr 1/29/14 2nd Qtr 5/23/14 3rd Qtr 8/27/14 4th Qtr 10/30/14 1st Qtr 3/18/15 2nd Qtr 6/11/15 <1,0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 140 62 110 300 NA NA <2.5 190 300 504 452 <5.0 <5.0 <5.0 500 350 660 470 <1.0 <1.0 <1.0 <1.0 NA 620 720 660 1,200 1,100 1,200 910 300 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 460 220 100 1,100 <1.0 <1.0 <1.0 <1.0 620 280 180 110 <1.0 <1.0 <1.0 <1.0 76 79 130 140 <1.0 <1.0 <1.0 <1.0 154 486 1,126 1,380 <1.0 <1.0 <1.0 <1.0 5.16 1,260 1,110 1,060 1,220 <1.0 <1.0 <1.0 1,210 1,240 <1.0 <1.0 6.2 1.6 1.5 NA NA <2.5 <2.5 <5.0 <5.0 <5.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <1 0 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA NA NA 52 50 54 61 58 ' 2 54 59 59 55 58 51 61 NA 64 62 51 51 48 42 38 52....32 42 41 45 40 46 44 45 49.1 51.5 67.9 70.9 73 77.3 74 75.2 78.6 75 1.6 0.8 1.1 3.3 2.4 3.5 6.8 5.7 7.3 5.1 7.3 6.7 7.3 9.9 9.23 10.5 11.6 9.8 8.1 3.8 5.0 1.6 0.8 11.0 9.0 3.3 1.9 1.16.9 0.8 1.0 1.6 1.2 5.6 13.0 16.0 168 13.9 9.8 13.2 15.0 11.4 NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (14 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride (5 M9/L)______ Chloroform (70 Ufl/L) Chloromethane (30 pg/L) Parameter (GWQS) Methylene Chloride ______(5 M9/L)_____ Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite ______(10 mg/L)______ TW4-11 (chloroform pumping well) 1 st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 11/18/08 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 1st Qtr 3/3/10 2nd Qtr 6/14/10 3rd Qtr 8/12/10 4th Qtr 10/15/10 1st Qtr 2/23/11 2nd Qtr 6/1/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 1st Qtr 1/24/12 2nd Qtr 6/13/12 3rd Qtr 9/13/12 4th Qtr 10/3/12 1st Qtr 2/13/13 2nd Qtr 6/18/13 3rd Qtr 9/12/13 4th Qtr 11/13/13 1st Qtr 2/5/14 2nd Qtr 5/23/14 3rd Qtr 8/27/14 4th Qtr 10/29/14 1st Qtr 3/9/15 2nd Qtr 6/11/15 NA NA <10 <100 <50 <50 <50 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 4,400 3,590 4,400 4,400 1.7 4,400 4,300 4,080 3,660 NA NA <10 <100 <50 <50 <50 NA NA <10 <100 <50 <50 <50 2.7 1.3 1.6 1.7 1.6 3,600 3,800 4,500 4,400 NA 340 640 900 1,000 1,000 980 1,000 860 <1.0 <1.0 <1.0 <1.0 <T0" <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 820 820 800 720 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0<1.6 <1.0 <1.0 <1.0 1,000 930 820 1500 <1.0 <1.0 <1.0 <1.0 610 660 740 730 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <10 <1.0 <1.0 <1.0 3.23 867 788 865 874 <1.0 <1.0 <1.0 <1.0 5.19 785 751 719 803 <1.0 <1.0 <1.0 1.2 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1.24 <1.0 2,450 2,710 <1.0 <1.0 <1.0 <1.0 NA NA NA 1.3 1.6 1.2 NA 58 56 56 55 55 54 53 53 53 63 46 42 47 NA 49 44 49 46 42 40 43 49 46 49 48 46 43 52 49 50 47.3 49.3 46.6 46.7 48.5 51.6 48 56.4 49.8 62.2 8.7 10.3 9.4 9.4 9.2 10.0 10.0 10.0 10.1 10.6 10.2 9.8 ...7.7 7.3 7.9 9.5 7.3 6.8 7.0 6.6 6.8 6.9 6.7 6.4 6.5 7.3 7.1 7.1 6.8 6.7 3 0 7.0 6.8 7.4 7.8 8.0 8.5 6.9 5.4 7.3 8.7 8.5 NA = not analyzed Bold and italics indicates the MDL exceeded the GWQS. Bold and italics indicates the MDL exceeded the GWQS. TABLE 1 (15 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride (5 pg/L) Chloroform (70 pg/L) Chloromethane (30 Pfl/L) Parameter (GWQS) Methylene Chloride (5 pg/L) Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-12 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 NA NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/16/09 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/23/10 2nd Qtr 6/14/10 3rd Qtr 8/10/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/15/11 2nd Qtr 5/25/11 3rd Qtr 8/16/11 4th Qtr 11/15/11 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/17/12 2nd Qtr 5/31/12 3rd Qtr 8/29/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/13/13 2nd Qtr 5/29/13 3rd Qtr 8/29/13 4th Qtr 11/6/13 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/22/14 2nd Qtr 5/21/14 3rd Qtr 8/27/14 4th Qtr 10/23/14 1st Qtr 3/11/15 ,2nd Qtr 6/10/15 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <10 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 5.8 1.0 NA NA <1.0 <1.0 2.6 1.4 1.4 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1 0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.6 <1.0 NA NA NA 19 19 16 16 16 16 18 29 16 16 19 18 22 23 22 22 23 22 29 35 31 31 32 31 30 28 34 39 39 36.7 38.6 41.7 41.4 41.6 40.2 47 50.2 50.6 56 1.4 1.6 1.5 1.4 1.3 1.4 1.4 1.4 1.5 1.5 1.4 1.4 1.6 2.7 2.7 2.5 2.4 3.8 5.1 3.6 4.0 11.0 9.0 8 0 6.5 7.0 6.8 8.0 ...7 7 10.0 13.0 13.0 12.6 14.2 17.4 16.4 18.4 17.0 13.0 16.1 19.2 18.8 NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (16 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride (5 pg/L) Chloroform -(70 pg/L) Chloromethane (30 mh/L) Parameter (GWQS) Methylene Chloride (5 pg/L) Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-13 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA <1.0 3.1 NA NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA NA 69 67 66 65 33 4.2 4.3 4.6 4.3 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/16/09 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/24/10 2nd Qtr 6/14/10 3rd Qtr 8/10/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/15/11 2nd Qtr 5/25/11 3rd Qtr 8/16/11 4th Qtr 11/15/11 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/17/12 2nd Qtr 5/31/12 3rd Qtr 8/29/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/13/13 2nd Qtr 5/29/13 3rd Qtr 8/29/13 4th Qtr 11/6/13 <1.0 <1.0 <1,0 <1.0 1st Qtr 1/22/14 2nd Qtr 5/21/14 3rd Qtr 8/13/14 4th Qtr 10/23/14 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/11/15 2nd Qtr 6/10/15 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1.7 1.4 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1,0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <T"cF <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.6 <1.0 59 59 58 58 54 58 50 58 58 57 63 60 53 53 55 55 60 56 60 54 55 59 60 60 59.3 56 63.5 58.5 63.1 56.1 62 66.1 66.4 70.3 4.2 4.9 4.3 0.8 4.6 4.6 4.4 4.1 3.8 4.2 4.3 4.6 3.7 1.2 4.7 4.1 4.3 5.2 5.6 5.8 5.5 6.4 5.2 5.9 5.5 6.0 6.2 5.9 6.3 6.8 7.2 6.5 7.1 6.0 4.8 6.3 7.1 6.3 NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (17 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride (5 pg/L) Chloroform (70 ug/L) Chloromethane (30 ua/L) Parameter (GWQS) Methylene Chloride _____(5 pg/L)_____ Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite ______(10 mg/L)______ TW4-14 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NS NS NS NS 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 NS NS NS <1.0 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/16/09 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/3/10 2nd Qtr 6/14/10 3rd Qtr 8/10/10 4th Qtr 10/15/10 1st Qtr 2/15/11 2nd Qtr 6/14/11 3rd Qtr 8/16/11 4th Qtr 11/15/11 1st Qtr 1/17/12 2nd Qtr 6/14/11 3rd Qtr 8/29/12 4th Qtr 10/3/12 <10 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1 0 <1.0 <1.0 <1.0 1st Qtr 2/7/13 2nd Qtr 5/29/13 3rd Qtr 8/29/13 4th Qtr 11/6/13 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/22/14 2nd Qtr 5/21/14 3rd Qtr 8/13/14 4th Qtr 10/23/14 1st Qtr 3/12/15 2nd Qtr 6/10/15 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NS NS NS NS NS NS NS NS <1.6 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NS NS NS NS NS NS NS <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0<1.6 <1.0 <1.0 <1.0 1.7 1.82 <1.0 <1.0 NS NS NS NS NS NS NS <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <10 <1.0 NS NS NS NS NS NS NS NS NS NS NS NS NS NS 37 38 38 36 38 57 35 34 40 35 36 38 34 33 49 35 29 25 24 33 15 20 35 37 37 35.2 38.6 37.6 36.5 35.5 32.5 38 38.9 40.1 41.8 2.4 2.3 1.4 1.1 0.8 0.4 1.6 1.38 0.76 1.6 1.4 1.5 1.4 2 5 2.9 2.8 2.9 1.8 1.4 2.6 1.7 1.9 3.3 3.9 3.9 4.6 4.4 4.5 4.8 5.9 4.9 4 1 5.2 5.2 3.6 NS = not sampled Shaded indicates concentrations exceeding GWQS. TABLE 1 (18 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride ______(5 H9'l)______ Chloroform (70 pg/L) Chioromethane ___(Mjjfl/U___ Parameter (GWQS) Methylene Chloride (5 MH/L) Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-16 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <1.0 <1.0 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/17/09 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/24/10 2nd Qtr 6/14/10 3rd Qtr 8/24/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <10 1st Qtr 2/22/11 2nd Qtr 5/26/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 (1) 12/7/11 <1.0 <1.0 <1.0 NA <1.0 1st Qtr 1/18/12 2nd Qtr 5/26/11 3rd Qtr 8/30/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/7/13 2nd Qtr 5/30/13 3rd Qtr 9/5/13 4th Qtr 11/7/13 1st Qtr 1/29/14 2nd Qtr 5/22/14 3rd Qtr 8/14/14 <2)3rd Qtr 9/24/14 4th Qtr 10/29/14 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/12/15 2nd Qtr 6/11/15 <1.0 <1.0 240 212 85 14 NA NA 39 13 5.2 13.6 <1.0 <1.0 8.7 2.6 7.1 1.4 <1.0 <1.0 <1.0 <1.0 <1.0 11 10 3.9 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 2.1 4.3 3 <1.0 <1.0 <1.0 <1.0 15 16 9.2 NA <1.0 <1.0 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 13.4 <1.0 <1.0 <1.0 <1.0 6.93 14.6 229 371 387 <1.0 <1.0 <1.0 <1.0 <1.0 153 65.3 <1.0 <1.0 NA NA 3.2 2.6 1.1 2.4 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 43 5.9 NA NA NA 21 8.9 2.7 9.2 6.6 1.8 5.1 1 26 14 6.6 1.4 1.7 NA 4.21 <0.1 <0.1 <0.1 64 60 55 60 62 79 75 65 69 52 58 71 89 73 76 79 76 77 64 72 71 86 81 63 38 48 53 59 59 <0.1 <0.1 <0.1 58.1 49.8 54.4 56.6 <0.1 <0.1 <0.1 66.8 80.7 80 NA 92.1....65 61 1.4 ...3 1.9 2.7 5.6 12.3 9.9 5.4 4.4 <0.1 1.5 10.5 9.8 9.6 8.9 8.8 5.2 4.2 4.7 4.6 3.3 7 5 1.7 0.4 0.1 1.4 ...3 2 4.9 5.1 NA 8.4 4 3 1.06 (1) VOCs were resampled because laboratory missed holding (2) VOCs were resampled NA = not analyzed Shaded indicates concentrations exceeding GWQS. time. TABLE 1 (19 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride (5 Mg/L) Chloroform (70 Mg/L) Chloromethane (30 pg/L) Parameter (GWQS) Methylene Chloride (5 iifl/L) Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-18 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <1.0 <1.0 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/22/09 1st Qtr 2/24/10 2nd Qtr 6/14/10 3rd Qtr 8/12/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/22/11 2nd Qtr 5/26/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 <1) 12/7/11 <1.0 <1.0 <1.0 NA <1.0 1st Qtr 1/18/12 2nd Qtr 6/13/12 3rd Qtr 9/11/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/13/13 2nd Qtr 6/13/13 3rd Qtr 9/5/13 4th Qtr 11/13/13 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/30/14 2nd Qtr 5/22/14 3rd Qtr 8/14/14 4th Qtr 10/28/14 1st Qtr 3/12/15 2nd Qtr 6/11/15 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA 38 29.8 39 14 NA NA 12 12 10.8 12.5 <1.0 <1.0 9.2 8 8.9 7.4 6.4 5.7 8 9.4 <1.0 <1.0 <1.0 <1.0 <1 0 <1.0 <1.0 <1.0 11 16 13 8.2 69 29 29 30 39 26 29 28 <1.0 <1.0 <1.0 <1.0 <1 0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <1.0 25 24 38 30 <1.0 <1.0 <1.0 <1.0 34.9 37.9 41 44.3 <1.0 <1.0 <1.0 <1.0 6.93 6.93 32.8 33 32 30.5 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 2.8 1.1 1.6 2.7 NA NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 <1.0 <i.6 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 <1.0 <T6 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA NA 41 36 35 35 34 30 28 32 27 23 23 26 30 29 30 26 30 41 35 37 50 52 36 23 23 NA 18 30 26 27 NA 23.1 22.9 36.2 37.1 38.9 47 49 40.8 41.6 43.5 14.1 12.9 13.3 7.3 5.9 4.7 6.1 5.7 5.1 4.9 5.0 4.4 0.7 4.6 4.9 5.2 5.2 6.2 5.9 5.4 5.1 9.0 9.0 10.0 10.0 9.0 4.6 6.3 4.4 6.6 6.6 6.0 5.6 8.9 12.1 14.2 12.8 12.2 9.8 11.1 11.7 9.69 (1) VOCs were resampled because laboratory missed holding time. NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (20 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride (5 pg/L) Chloroform (70 pg/L) Chloromethane ___(30 pg/L)___ Parameter (GWQS) Methylene Chloride (5 Pfl/L) Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite ______(10 mg/L)______ TW4-19 chlorofrom pumping well 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <5.0 <50 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <50 <50 <50 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 <1.0 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/22/09 1st Qtr 2/17/10 2nd Qtr 6/14/10 3rd Qtr 8/16/10 4th Qtr 10/15/10 1st Qtr 2/17/11 2nd Qtr 6/7/11 3rd Qtr 8/17/11 4th Qtr 11/17/11 (1) 12/5/11 1st Qtr 1/23/12 2nd Qtr 6/6/12 3rd Qtr 9/4/12 4th Qtr 10/3/12 1st Qtr 2/13/13 2nd Qtr 6/5/13 3rd Qtr 9/3/13 4th Qtr 10/29/13 1st Qtr 1/27/14 2nd Qtr 5/19/14 3rd Qtr 8/11/14 4th Qtr 10/21/14 1st Qtr 3/9/15 2nd Qtr 6/8/15 1.6 13 1.9 1.9 2.9 8.6 ' 12 1.2 1.2 15 16 1.3 4.2 4.9 1.3 17 8.3 2.1 5.4 1.5 1.1 3.5 4 5.15 5.15 20.7 6.42 4.05 5.51 1.9 4.8 8.92 2.62 2,200 1,200 1,400 2,800 NA NA <5.0 <50 1,200 1,100 1,120 1,050 <50 <50 <50 1,200 1,100 1,100 1,800 1,000 3,600 4,200 1,100 990 6,600 4,700 940 1,800 2,000 1,200 3,400 4,000 970 2,200 650 460 950 1500 4,210 2,070 8,100 942 586 810 1,410 4,310 4,660 1,570 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 8.3 <1.0 <1.0 <1.0 2.6 NA NA <5.0 <50 <50 <50 <50 <1.0 NA NA NA 81 86 116 <1.0 Did not sample <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1,0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <0.1 123 134 133 129 132 131 128 113 124 127 132 43 124 144 132 142 146 135 148 148 148 138 149 149 150 164 148 179 134 134 152 140 130 238 180 5.3 5.7 4.6 4 5.2 4.3 4.6 4 4.1 4 ...2.2 2.8 35.2 47.8 3.2 2.4 <0.1 26.7 2 4 4 5.9 2.7 17.0 12.0 3.0 5.0 0.6 2.4 2.5 4.1 8.0 3.0 17.6 4.7 1.6 1.3 1.6 4.7..8.56 0.916 (1) VOCs were resampled because laboratory missed holding time. NA = not analyzed Bold and italics indicates the MDL exceeded the GWQS. Shaded indicates concentrations exceeding GWQS. TABLE 1 (21 of 27) Historic Summary Of Monitoring Parameters Up To The 3nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride ______(5 pg/L)______ Chloroform (70 jig/L) Chloromethane ___(30 M9/L)___ Parameter (GWQS) Methylene Chloride _____(5 pg/L)_____ Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-20 chloroform pumping well 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA <10 <250 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <500 <500 <1000 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 NA 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/14/09 1st Qtr 2/17/10 2nd Qtr 6/14/10 3rd Qtr 8/16/10 4th Qtr 10/15/10 1st Qtr 2/23/11 2nd Qtr 6/1/10 3rd Qtr 8/17/11 4th Qtr 11/16/11 1st Qtr 1/23/12 2nd Qtr 6/6/12 3rd Qtr 9/4/12 4th Qtr 10/3/12 1st Qtr 2/11/13 2nd Qtr 6/5/13 3rd Qtr 9/3/13 4th Qtr 10/29/13 1st Qtr 1/27/14 2nd Qtr 5/19/14 3rd Qtr 8/11/14 4th Qtr 10/21/14 1st Qtr 3/9/15 2nd Qtr 6/8/15 7.1 3.1 2.2 3.5 6.8 9 13 15 5.7 4.9 8.4 14 2.7 11 12 20 27 10 7.3 7.2 10 33 26 22 19.6 32.5 25.7 17.3 18.4 22.1 14.1 18.5 20.8 16.2 39.000 3,800 19.000 9,200 61,000 5,300 11,000 4,400 1,800 5,200 9,000 13.000 30.000 21.000 NA 8,200 6,800 13.000 15.000 3,500 18,000 15.000 24.000 31,000 8,100 3,800 7,900 11000 36.000 13.000 19.000 18,500 26,300 26,800 15,700 17,800 22,100 12,400 23,300 19,900 17,600 NA <10 <250 <500 <500 <1000 <1.0 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 NA <1 0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 4.04 4.85 13.4 Monitor well was not installed NA <10 <250 <500 <500 1.9 2.31 55.2 <1000 <1.0 NA <1.0 <1.0 <1.0 2.2 1.1 1.8 1.9 1.5 1.2 3.7 5.2 4.2 4.4 3.0 3.2 3.7 2.2 5.5 19.0 2.1 3.1 2.5 1.3 1.21 1.3 2.14 1.37 2 04 3.98 2.2 2.38 1.38 1.73 NA NA 131 120 235 134 124 124 112 117 170 132 191 156 168 164 164 153 187 179 200 196 203 220 177 207 186 207 262 289 302 252 250 260 272 254 269 299 292 290 296 10.10 2.90 1.80 3.80 9.40 2.90 3.50 4.20 2.30 2.10 5.60 0.90 8.00 4.44 5.51 5.10 2.90 3.30 5.30 2.00 5.60 5.30 4.60 4.40 4.80 6.50 4.20 7.90 11.00 10.80 11.00 9.07 9.80 8.65 9.64 7.56 5.95 4.30 7.67 9.80 5.76 (1) VOCs were resampled because laboratory missed holding time. NA = not analyzed Bold and italics indicates the MDL exceeded the GWQS. Shaded indicates concentrations exceeding GWQS. TABLE 1 (22 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride ______(5 M9/L)______ Chloroform (70 pg/L) Chloromethane ___(30 H9/L)___ Parameter (GWQS) Methylene Chloride ______(s vaM_____ Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-21 (chloroform pumping well) 1st Qtr 3/16/05 2nd Qtr 5/25/05 NA 3rd Qtr 8/31/05 <5.0 4th Qtr 12/7/05 <1.0 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 11/18/08 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/22/09 <2.5 <2.5 <2.5 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 2 1 8 5.8 7 1.7 1.6 192 78 86 120 120 108 139 160 300 140 120 NA 390 180 120 170 180 200 200 160 170 210 390 200 NA <5.0 <1.0 <2.5 <2.5 <2.5 <1.0 Monitor well was not installed NA <5.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 <1.0 <2.5 <2.5 <2.5 <1.0 <10 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 NA NA NA 353 347 318 357 296 306 327 300 288 331 271 244 284 279 291 281 256 228 266 278 210 303 290 287 287 NA 14.6 10.1 9.6 8.5 10.2 8 9 8.7 8.7 8.6 8.6 8.3 14.3 8.8 7.57 8.0 8.3 8.1 9.2 8.4 8.4 12.0 14.0 7.0 ' 9.0 12.0 14.0 13.0 1st Qtr 2/25/10 2nd Qtr 614/10 3rd Qtr 8/13/10 4th Qtr 10/15/10 <1.0 <1.0 1st Qtr 2/22/11 2nd Qtr 6/28/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 <1) 12/7/11 1st Qtr 1/19/12 2nd Qtr 6/13/12 3rd Qtr 9/13/12 4th Qtr 10/4/12 1st Qtr 2/13/13 2nd Qtr 6/18/13 3rd Qtr 9/13/13 4th Qtr 11/13/13 <1.0 1st Qtr 2/5/14 2nd Qtr 5/22/14 3rd Qtr 8/27/14 4th Qtr 10/29/14 <1.0 1.04 1st Qtr 3/12/15 2nd Qtr 6/8/15 1.75 1.92 9.2 1.2 T2 4.8 6 3 6.7 <1.0 <1.0 <1.0 <1.0 230 290 460 390 6.4 5.4 6 7 5.25 3.49 2.13 420 400 410 390 282 328 244 204 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 6.23 4.73 220 240 204 229 <1.0 <1.0 <1.0 <1.0 2.04 2.04 <1.0 <1.0 292 366 <1.0 <1.0 <1.0 <1.0 228 285 142 270 221 243 207 206 200 243 230 252 255 494 15.0 11.0 13.0 14.0 11.8 13.8 10.3 9.0 11.4 11.5 7.1 10.0 10.9 13.1 (1) VOCs were resampled because laboratory missed holding time. NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (23 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride (5 pg/L) Chloroform (70 pg/L) Chloromethane (30 pg/L) Parameter (GWQS) Methylene Chloride (5 ug/L) Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite ______(10 mg/L)______ TW4-22 nitrate pumping well 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA <5.0 <5.0 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <10 <10 <10 <1.0 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 11/18/08 <1.0 <1.0 NA <2.0 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 <1.0 <1.0 <10 <1.0 1st Qtr 3/3/10 2nd Qtr 6/14/10 3rd Qtr 8/24/10 4th Qtr 10/15/10 <10 <1.0 <1.0 <1.0 1st Qtr 2/22/11 2nd Qtr 6/1/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 0) 12/7/1 <1.0 <1.0 NA <1.0 1st Qtr 1/19/12 2nd Qtr 6/13/12 3rd Qtr 9/12/12 4th Qtr 10/4/12 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/11/13 2nd Qtr 6/5/13 3rd Qtr 9/3/13 4th Qtr 10/29/13 1st Qtr 1/27/14 2nd Qtr 5/19/14 3rd Qtr 8/11/14 4th Qtr 10/29/14 1st Qtr 3/9/15 2nd Qtr 6/8/15 1.3 1.2 3.24 3.35 3.25 8.09 6.06 6.65 1.9 3.32 3.77 2.42 NA NA 340 290 320 390 280 864 350 440 740 530 440 1,400 1,200 6,300 630 390 730 2,300 380 2,200 540 340 340 1,300 210 450 400 200 120 121 330 10,600 12,500 9,640 13,300 12,100 12,400 12,400 12,400 12,700 8,050 NA <5.0 <5.0 <10 <10 <10 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <10 <1.0 NA <1.0 <TC <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 Monitor well was not installed NA <5.0 <5.0 <10 <10 <10 1.6 <1.0 40 1.61 4 31 3.42 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 2.83 NA NA NA 253 236 221 221 236 347 273 259 238 519 271 524 539 177 177 391 175 427 134 130 134 114 138 120 174 NA 36 35 130 130 586 487 501 598 614 540 596 675 390 NA NA 18.2 15.7 15.1 15.3 14.3 14.5 15.9 20.9 19.3 19.3 18.8 39.1 41.9 38.7 36.3 20.7 20.6 40.3 17.8 36.8 19.0 15.0 16.0 18.0 17.0 15.0 19.0 14.0 12.8 7.0 14.0 58.0 50.2 29.7 45.2 54.6 47.2 41.5 54.9 69.2 47.1 (1) VOCs were resampled because laboratory missed holding time. NA = not analyzed Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS. TABLE 1 (24 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride ______(5 ng/L) Chloroform (70 H9'L) Chloromethane (30 Pfl/L) Parameter (GWQS) Methylene Chloride (5 pg/L) Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-23 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 11/18/08 <1.0 <1.0 <1.0 <10 <1.0 <1.0 NA <2.0 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/16/09 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/24/10 2nd Qtr 6/14/10 3rd Qtr 8/24/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/16/11 2nd Qtr 6/14/11 3rd Qtr 8/16/11 4th Qtr 11/15/11 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/17/12 2nd Qtr 5/31/12 3rd Qtr 8/29/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/7/13 2nd Qtr 5/30/13 3rd Qtr 9/5/13 4th Qtr 11/7/13 1st Qtr 1/23/14 2nd Qtr 5/19/14 3rd Qtr 8/13/14 4th Qtr 10/28/14 1st Qtr 3/12/15 2nd Qtr 6/8/15 <1.0 <1.0 <1.0 <1.0 <1 0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA 47 46 43 <0.1 <0.1 <0.1 41 41 35 51 <0.1 <0.1 <0.05 <0.05 NA 41 43 43 37 <0.1 <0.1 <0.1 <0,1 45 40 40 34 <0.1 <0.1 <0.1 <0.1 44 44 41 43 <0.1 <0.1 <0.1 <0.1 40 44 46 45 <0.1 <0.1 <0.1 <0.1 43.6 44.7 48 43 <0.1 0.1 <0.1 <0.1 44.6 42.3 46 46.8 <0.1 <0.1 <0.1 <0.1 47.3 48.4 <0.1 <0.1 NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (25 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride (5 Hfl'L) Chloroform (70 ML) Chloromethane (30 pg/L) Parameter (GWQS) Methylene Chloride (5 pg/L) Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-24 nitrate pumping well 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 11/18/08 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/16/09 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/25/10 2nd Qtr 6/14/10 3rd Qtr 8/24/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/17/11 2nd Qtr 5/26/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 (1) 12/7/11 1st Qtr 1/16/12 2nd Qtr 6/6/12 3rd Qtr 8/30/12 4th Qtr 10/3/12 1st Qtr 2/11/13... 2nd Qtr 6/5/13 3rd Qtr 8/30/13 4th Qtr 10/29/13 <1.0 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/27/14 2nd Qtr 5/19/14 3rd Qtr 8/11/14 4th Qtr 10/21/14 1st Qtr 3/9/15 2nd Qtr 6/8/15 2.6 2.2 1.5 <1.0 <1.0 <1.0 1.5 1.4 2.9 NA <2.0 NA 1.4 1.5 1.4 1.2 1.3 1.7 1.8 1.4 1.8 1.1 1.7 1.2 <1.0 <1.0 <1.0 NA <2.0<1.6 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0<1.6 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1 17.4 21.8 32.5 1.18 <1.0 <1.0 <1.0 <1.0 <1.0 78.5 62.7 76.3 25.8 49.2 4.28 <10 <1,0 <1.0 <1.0 <1.6 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA 770 791 692 740 834 1180 1130 NA 1010 759 618 1080 896 639 587 522 ii 66 mo 967 608 NA 373 355 489 405 1260 916 998 1030 809 1020 1150 1050 944 1290 26.1 29 24.7 244 45.3 38.4 44.8 30.5 30.4 30.7 28.3 33.1 30 31 31 31 35 34 35 37 37 37 38 35.9 23.7 33 35 31.6 35.0 31.5 35.7 34.6 31.8 (1) VOCs were resampled because laboratory missed holding time. NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (26 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event TW4-25 nitrate pumping well 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 4th Qtr 11/18/09 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/14/09 1st Qtr 2/23/10 2nd Qtr 6/14/10 3rd Qtr 8/10/10 4th Qtr 10/15/10 1st Qtr 2/16/11 2nd Qtr 5/25/11 3rd Qtr 8/16/11 4th Qtr 11/15/11 1st Qtr 1/16/12 2nd Qtr 5/31/12 3rd Qtr 9/4/12 4th Qtr 10/3/12 1st Qtr 2/11/13 2nd Qtr 6/5/13 3rd Qtr 9/4/13 4th Qtr 10/31/13 1st Qtr 1/27/14 2nd Qtr 5/19/14 3rd Qtr 8/11/14 4th Qtr 10/21/14 1st Qtr 3/9/15 2nd Qtr 6/8/15 Carbon Tetrachloride (5 Mfl/L) <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1,0 <1.0 <1.0 <1.0 <1.0<1.6 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0<1.6 <1.0 <1.0 <1.0 <1.0 <1.0 <1,0 <1.0 <1.0 <1.0 Chloroform (70 pg/L) <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 2.2 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1.8 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0<1.6 <1.0 Chloromethane (30 pg/L) <1.0 <1.0 <1.0 <1 0 <1.0 <1.0 NA <2.0 <1.6 <1.0 <1.0 <1.0 <1.6' <1.0 <1.0 <1.0 <1 0 <1.0 <1.0 <1.0 <1.0 <1.0 <1,0 <1.0 <1 0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 Parameter (GWQS) Methylene Chloride (5 pg/L) <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 Chloride No GWQS (mg/L) 395 382 358 374 344 333 366 NA 332 328 328 371 296 306 250 312 315 321 276 294 304 287 334 338 190 136 119 88.6 85.7 51.1 67 58.1 310 58.3 Nitrate, Nitrate + Nitrite (10 mg/L) 17.1 29 17 18.7 22.1 18.8 21.3 NA 15.3 15.3 3.3 14.2 14.4 16 14 15 15 16 16 16 16 16 17 17 9.04 5 24 6 6 2.2 1.2 1.6 1 14.4 1 (1) VOCs were resampled because laboratory missed holding time. NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (27 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter (GWQS) Carbon Tetrachloride (5 mH/L) Chloroform (70 pg/L) Chloromethane ___(30 pg/L)___ Methylene Chloride _____(5 vaM______ Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite ______(10 mg/L)______ TW4-26 2nd Qtr 6/14/10 3rd Qtr 8/24/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 1st Qtr 2/16/11 2nd Qtr 5/26/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 <1) 12/7/11 <1.0 <1.0 <1.0 NA <1.0 1st Qtr 1/18/12 2nd Qtr 6/6/12 3rd Qtr 9/11/12 4th Qtr 10/3/12 1st Qtr 2/7/13 2nd Qtr 6/13/13 3rd Qtr 9/5/13 4th Qtr 11/7/13 <1.0 <1.0 <1.0 <1.0<1.6 <1.0 <1.0 <1.0 1st Qtr 1/29/14 2nd Qtr 5/21/14 3rd Qtr 8/11/14 4th Qtr 10/28/14 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/12/15 2nd Qtr 6/10/15 <1.0 <1.0 NA 13 5.2 5.4....2 2.9 2.8 5.2 <1.0 <1.0 <1.0<1.6 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <1.0 7 4.1 4.9 4.9 4.9 2.12 2.81 3.37 1.43 4.23 1.3 2.45 2.37 6.12 <1.0 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <10 <1.0 1.17 <1.0 <1.0 NA 33 17 22 30 15 19 26 NA 17 19 19 19 16.6 14.5 17.6 15.9 16.9 15.4 15 14.6 14.4 14.4 7.9 9.0 9.6 10.0 10.0 11.0 10.0 11.0 12.0 9.0 12.0 12.5 13.6 11.7 15.9 14.2 12.5 10.8 12.3 144 11.3 TW4-27 1st Qtr 1/18/12 2nd Qtr 6/13/12 3rd Qtr 9/4/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/7/13 2nd Qtr 6/13/13 3rd Qtr 8/30/13 4th Qtr 11/6/13 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/23/14 2nd Qtr 5/21/14 3rd Qtr 8/13/14 4th Qtr 10/28/14 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/11/15 2nd Qtr 6/10/15 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1,0 <1.0 <1.0 <1,0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 11 17 21 18 18.8 20.3 19 21.8 31.8 20.6 23 24.4 26.2 26.8 24.0 41.0 37.0 36.0 31.2 29.4 27.2 29.8 31.3 31.1 27.0 28.2 26.5 24.0 TW4-28 2nd Qtr 6/19/13 3rd Qtr 8/29/13 4th Qtr 11/6/13 <1.0 <1.0 <1.0 1st Qtr 1/22/14 2nd Qtr 5/21/14 3rd Qtr 8/13/14 4th Qtr 10/23/14 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/11/15 2nd Qtr 6/10/15 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1,0 <1.0 <10 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 44.6 45.3 45.3 47.8 45.7 50 52.1 52.2 56.4 14.9 17.3 16.2 16 9 16.5 14.2 16.5 19.0 19.0 TW4-29 2nd Qtr 6/19/13 2nd Qtr 7/11/13 3rd Qtr 9/26/13 4th Qtr 11/13/13 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/5/14 2nd Qtr 5/22/14 3rd Qtr 8/27/14 4th Qtr 10/29/141st Qtr 3/12/15... 2nd Qtr 6/11/15 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 242 262 246 260 258 262 242 290 299 329 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 44.8 37.7 41.4 42.5 14.9 38.2 41 41 40.5 42.5 4 60 3.52 4,18 4.11 4.63 3.52 3.40 3.64 4.14 2.95 (1) VOCs were resampled because laboratory missed holding time. NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (27 of 27) Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2015 Chloroform Contamination investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride ______(5 M9/L)______ Chloroform (70 pg/L) Chloromethane ___(30jifl/LJ___ Parameter (GWQS) Methylene Chloride _____(5 pg/L)_____ Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-30 2nd Qtr 6/19/13 3rd Qtr 9/26/13 4th Qtr 11/13/13 <1.0 <1.0 <1.0 1st Qtr 1/23/14 2nd Qtr 5/22/14 3rd Qtr 8/13/14 4th Qtr 10/23/14 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/11/15 2nd Qtr 6/11/15 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1.65 2.25 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 36 36.3 35.9 36.9 31.9 38 37.1 38.3 40.3 1.0 1 1.2 1.4 1.4 1.5 1.8 2.15 1.75 TW4-31 2nd Qtr 6/19/13 3rd Qtr 9/5/13 4th Qtr 11/7/13 <1.0 <1.0 <1,0 1st Qtr 1/23/14 2nd Qtr 5/21/14 3rd Qtr 8/13/14 4th Qtr 10/28/14 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/11/15 2nd Qtr 6/10/15 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1,0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 28.4 29.4 28 28.5 26.3 30 37.1 30.6 31.1 1.3 1.1 1.3 1.3 1.2 1.1 1.8 ........... 1.2 TW4-32 4th Qtr 11/14/13 <1.0 1st Qtr 1/22/14 2nd Qtr 5/21/14 3rd Qtr 8/13/14 4th Qtr 10/23/14 1st Qtr 3/11/15 Duplicate TW-65 2nd Qtr 6/10/15 <1.0 <1.0 <1.0 <1.0 <10 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1,0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1,0 <1.0 <1.0 <1.0 <1.0 52.1 54.5 54.9 64 62.6 64.2 65.9 62.7 4.3 5.1 5.6 4.2 2.1 2.5 2.25 1.2 TW4-33 4th Qtr 11/14/13 <1.0 1st Qtr 1/30/14 2nd Qtr 5/22/14 3rd Qtr 8/27/14 4th Qtr 10/29/14 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/12/15 2nd Qtr 6/11/15 <1.0 <1.0 126 124 121 104 124 134 127 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1,0 <1.0 <1.0 <1.0 47.2 43.5 46.8 43 44.2 44.2 46.6 1.82 2.56 1.63 1.50 2.22 T91 1.62 TW4-34 4th Qtr 11/14/13 <1.0 1st Qtr 1/23/14 2nd Qtr 5/22/14 3rd Qtr 8/13/14 4th Qtr 10/29/14 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/11/15 2nd Qtr 6/11/15 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 19.2 29.4 17.9 18 17.8 17.7 17.4 1.64 1.93 1.69 1.10 1.16 1.21 0.868 TW4-35 3rd Qtr 8/27/14 4th Qtr 10/28/14 <1.0 <1.0 1st Qtr 3/11/15 2nd Qtr 6/10/15 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.6 <1.0 34 34.1 34.9 35.2 0.2 0.351 0.436 0.452 TW4-36 3rd Qtr 8/27/14 4th Qtr 10/23/14 <1.0 <1.0 1st Qtr 3/11/15 2nd Qtr 6/10/15 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 65 67.3 67.2 69.3 <0.1 <0.1 <0.1 <0.1 TW4-37(chloroform pumping well) 2nd Qtr 6/8/15 118.2 |30,200 15.7 11.94 3451 35.2 Shaded indicates concentrations exceeding GWQS. (1) VOCs were resampled because laboratory missed holding time.